The Mickelson comments in question came in response to a tweet from Rickie Fowler’s caddie Joe Skovron. Skovron tweeted in defense of green-reading books, which have come under fire as a potential contributor to slow play on Tour. Skovron, on the other hand, wrote, “I don’t buy blaming them for slow play.”

But he wasn’t done there. Mickelson continued the argument, writing, “Let me add the countless hours and many days it saves me preparing for tournaments throughout the year. The book gives me info on where I can/can’t miss it and still get up and down as well as best approach shot into the green without having to play multiple practice rounds.”

Let me add the countless hours and many days it saves me preparing for tournaments throughout the year. The book gives me info on where I can/can’t miss it and still get up and down as well as best approach shot into the green without having to play multiple practice rounds.

When a legendary name such as Phil Mickelson wades into the conversation, people are going to take notice, and some of Mickelson’s fellow pros responded in kind. Ian Poulter announced his support for Mickelson’s opinion.

Former World No. 1 Luke Donald, however, feels very differently and seemed to take exception with Mickelon’s use of the word “idiotic.”

“I guess I’m an idiot then,” Donald tweeted. “One thing I don’t understand here is for a greens book to be effective you have to know exactly where your ball is on the green relative to the hole – how can you have done 80% of your read then before you’ve even got to the green??”

Guess I’m an idiot then 🙋🏼‍♂️

One thing I don’t understand here is for a greens book to be effective you have to know exactly where your ball is on the green relative to the hole - how can you have done 80% of your read then before you’ve even got to the green?? 🤔 #banthemisayhttps://t.co/aVcz3ICMlK

Whatever your opinion is about green-reading books and their contribution to pace of play, we can be sure of one thing: the slow play is the hot topic on the PGA Tour, and if big names like Lefty keep offering their opinion publicly, it will stay that way for a long time.